This section introduces aspects that may be helpful to facilitating a better understanding of the invention. Accordingly, the statements of this section are to be read in this light. The statements of this section are not to be understood as admissions about what is in the prior art or what is not in the prior art.
There are many optical applications where the use of reflective optics (e.g., mirrors) is preferred over the use of refractive optics (e.g., lenses). For instance, in optical devices ranging from telescopes to micro-electro-mechanical systems (MEMS), it is often important to make a device that is as compact as possible. Optical components using reflective optics can provide smaller focal distances and less signal losses than optical components using refractive optics, thereby allowing the miniaturization of optical devices. Another advantage is that the reflectivity of mirrors can be made insensitive to wavelength, reducing chromatic aberrations. In addition, mirrors can function in spectral regions where diffractive optics cannot, e.g., in the ultraviolet and in the infrared.
Some currently available optical components that use reflective optics have limited capabilities, however. This in turn, limits their scope of application, or limits the extent of device miniaturization. For example, certain MEMS have mirrors made of solid material. These solid mirrors have no or limited ability to change their curvature. Additionally, the mirrors in MEMS can deflect an incoming light beam over a limited range because the mirror has a limited range of rotation.
There are also situations where it is desirable to use both reflective and refractive optics in a complementary fashion. In such cases, it is advantageous if optical components using reflective and refractive optics can both be fabricated using similar manufacturing processes. However, the mirrors of conventional MEMS are often fabricated in a fashion that has no analogous process for the manufacture of lens. Therefore two different fabrication processes have to be used to create mirrors and lenses, thereby increasing the cost and complexity of constructing the MEMS.
Embodiments of the invention overcome these deficiencies by providing an apparatus that uses a liquid mirror and methods of manufacturing and use.